Air discharge assembly unit, especially for routing air into the interior space of a vehicle

ABSTRACT

An air discharge assembly unit, especially for routing air (L) into the interior space ( 70 ) of a vehicle, includes an air routing duct ( 28 ) for routing primary air (H) from a primary air inlet area ( 18 ) to an air outlet area ( 40 ). A flow cross-sectional area of the air routing duct ( 28 ) decreases, at least in some areas away from the primary air inlet area ( 18 ), in the direction of the air outlet area ( 40 ) up to a duct area ( 30 ) with minimal flow cross-sectional area. A secondary air inlet area ( 41 ) is provided for the inlet of secondary air (N) into the air routing duct ( 28 ), in the area of the duct area ( 30 ), with minimal flow cross-sectional area.

CROSS REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of priority under 35 U.S.C. §119 ofDE 10 2013 208 944.9 filed May 15, 2013, the entire contents of whichare incorporated herein by reference.

FIELD OF THE INVENTION

The present invention pertains to an air discharge assembly unit, whichcan be used to route air into the interior space of a vehicle.

BACKGROUND OF THE INVENTION

In vehicles that are also used for transporting persons, especiallyambulances or rescue vehicles, the air, which is heated, for example, ina fuel-operated air heater, is introduced, in general, into the interiorspace of the vehicle at discharge sites provided in the roof area. Thismeans that the heated air flows downward from the top. Persons standingin the interior space of the vehicle, for example, paramedics oremergency physicians in ambulances or rescue vehicles, have their headscomparatively close to these discharge sites. Since the air heated in avehicle heater may have a temperature in the range of 80° C. and higherespecially in case of heating operation with a comparatively high heatoutput, there is a risk that at least an unpleasant feeling may developif the distance is short between such a discharge site and a personlocated in the interior space of the vehicle, but it may possibly alsocompromise the physical performance capacity.

SUMMARY OF THE INVENTION

An object of the present invention is to provide an air dischargeassembly unit, especially for routing air into the interior space of avehicle, with which excessively intense thermal load can be avoided evenin the area close to the discharge site.

This object is accomplished according to the present invention by an airdischarge assembly unit, especially for routing air into the interiorspace of a vehicle, comprising

an air routing duct for routing primary air from a primary air inletarea to an air outlet area, wherein a flow cross-sectional area of theair routing duct decreases, at least in some areas, away from theprimary air inlet area in the direction of the air outlet area up to aduct area with minimal flow cross-sectional area, and

a secondary air inlet area for the inlet of secondary air into the airrouting duct in the area of the duct area with minimal flowcross-sectional area.

The air discharge assembly unit designed according to the presentinvention can be used such that primary air, heated, for example, by afuel-operated vehicle heater, is delivered through the air routing ductin the direction of the air outlet area and is introduced there into aninterior space of the vehicle, which is to be heated. A secondary airstream, which is combined with the primary air stream in the air routingduct, can be drawn off, for example, from the interior space to be fedwith the primary air stream through the secondary air inlet area, sothat an air stream is generated, which is composed of the primary airstream and the secondary air stream and it has, in general, a reducedtemperature compared to the primary air stream because of the mixingwith the secondary air stream which generally has a lower temperaturethan the primary air stream, even when the primary air stream is fedwith a comparatively high temperature. This lowering of the temperatureof the air stream being discharged from the air discharge assembly unittakes place without a reduction of the heat output of a heater beingnecessary, and it thus makes possible a comparatively rapid andefficient heating of the interior space of a vehicle without excessivethermal load even close to or at the discharge site(s). Since the airdischarge assembly unit, according to the present invention, operatesaccording to the principle of a Venturi nozzle, i.e., the secondary airstream is drawn due to the Venturi injection into a narrowed area of theduct area due to the reduced static pressure in this area, no assemblyunits that need to be operated, e.g., blowers or the like, are necessaryto achieve the thorough mixing of the primary air stream with thesecondary air stream.

To combine the primary air stream with the secondary air stream, i.e.,to guarantee the inlet of the secondary air stream into the primary airstream, it is provided that the secondary air inlet area comprises atleast one secondary air inlet opening, through which the secondary airis added to the primary air.

To guarantee efficient mixing of the secondary air with the primary air,it is provided that a primary secondary air inlet opening surrounds alongitudinal axis of the air routing duct in a ring-shaped pattern, andprovisions may, furthermore, be made for the primary secondary air inletopening to have a truncated cone-shaped opening cross-sectionalgeometry.

To make it possible to take the secondary air, for example, from theinterior space to be supplied, but possibly also from the surroundingarea, it is provided that the secondary air inlet area comprises atleast one secondary secondary air inlet opening, wherein at least onesecondary secondary air inlet opening is open toward a secondary airflow space leading to the at least one primary secondary air inletopening.

Since the at least one primary secondary air inlet opening ispositioned, in general, relative to a longitudinal axis of the duct,such that it radially directly adjoins the air routing duct or theprimary air stream, it is proposed, furthermore, that at least onesecondary secondary air inlet opening be arranged radially outside theat least one primary secondary air inlet opening relative to thelongitudinal axis of the air routing duct. It should be noted here thatpositioning of the at least one secondary secondary air inlet openingradially outside the at least one primary secondary air inlet openingdefines only a radial relative positioning, i.e., for example, theradial distance from the longitudinal axis of the duct in the area inwhich these inlet openings are provided. These different types ofsecondary air inlet openings may, of course, be arranged such that theyoverlap each other in the circumferential direction, but, in principle,also in different circumferential areas.

Feeding secondary air in the direction of the at least one primarysecondary air inlet opening with the lowest flow resistance possible canbe guaranteed by the secondary air flow space surrounding a longitudinalaxis of the duct in an essentially ring-shaped pattern.

To make it possible to influence the ratio at which primary air is mixedwith secondary air, it is proposed that a flow cross-sectional area ofat least one and preferably all secondary secondary air inlet openingsbe variable. For example, the flow cross-sectional area of at least onesecondary secondary air inlet opening may be variable between a minimalflow cross-sectional area, which may be at or in the range of zero, anda maximal flow cross-sectional area, which guarantees a maximalsecondary air stream.

To route the primary air in the direction of the air outlet area, it isproposed that a first part of the assembly unit have a duct wall for theair routing duct, wherein the duct wall is formed such that it tapers atleast in some areas away from the primary air inlet area. It should benoted here that the statement that the cannel wall is designed with atapering means that, for example, the distance between said wall and alongitudinal axis of the duct decreases in the direction of flow, andthis decrease may be linear or also non-linear, so that a correspondingreduction of the flow cross-sectional area enclosed by the duct wall isachieved.

Furthermore, the duct wall may provide the duct area with the minimalflow cross-sectional area, i.e., the duct area in the vicinity of whichthe secondary air enters the primary air, preferably in an end of saidduct wall located at a distance from the primary air inlet area.

Furthermore, a second assembly unit part may be provided according tothe present invention, and this second assembly unit part has an airoutlet opening for the primary air routed through the air routing ductand possibly also for the secondary air being added to the primary airthrough the at least one primary secondary air inlet opening. This airoutlet opening, which is located downstream of the at least one primarysecondary air inlet opening in the direction of flow, may provide, forexample, essentially the air outlet area.

To provide an enlargement of the flow cross section for the air streamin the direction away from the duct area with the minimal flowcross-sectional area and also from the area in which the secondary airis added to the primary air, it is proposed that the air outlet openinghave a larger flow cross-sectional area than the duct area with theminimal flow cross-sectional area. Provisions may be made now, inparticular, for at least one primary secondary air inlet opening betweenthe duct wall of the first assembly unit part and the second assemblyunit part to be limited in its area that provides the air outletopening.

It is provided according to another, especially advantageous aspect thatthe first assembly unit part have at least one first secondary openingarea, that the second assembly unit part have at least one secondsecondary opening area, and that the at least one first secondaryopening area and the at least one second secondary opening area to bemovable relative to one another preferably by rotating the secondassembly unit part relative to the first assembly unit part forproviding at least one secondary secondary air inlet opening withvariable flow cross-sectional area. The first and second secondaryopening areas may be formed, for example, in the circumferentialdirection between wall areas of the first assembly unit part and of thesecond assembly unit part, respectively, which said wall areas extend inthe direction of a longitudinal axis of the duct, and which said wallareas can be positioned overlappingly in the circumferential directionand provide a variable flow cross-sectional area for at least onesecondary secondary air inlet opening by rotating the two assembly unitparts relative to one another and by the change in the extent of theoverlap, which change is generated thereby.

The present invention pertains, furthermore, to an air routing systemfor routing air into a space area, preferably into the interior space ofa vehicle, comprising at least one air discharge assembly unit designedaccording to the present invention. A heater, for example, one operatedwith fuel, in which the air, which is taken up, for example, from theoutside, is heated and then routed in the direction of the at least oneair discharge assembly unit, can be associated with the air routingsystem, especially if the air to be introduced into the interior spaceof the vehicle is to be treated thermally, i.e., for example, heated.

Further, provisions may be made in the air routing system for the airoutlet area as well as least one secondary secondary air inlet openingto be open towards the space area.

The present invention will be described in detail below with referenceto the figures attached. The various features of novelty whichcharacterize the invention are pointed out with particularity in theclaims annexed to and forming a part of this disclosure. For a betterunderstanding of the invention, its operating advantages and specificobjects attained by its uses, reference is made to the accompanyingdrawings and descriptive matter in which preferred embodiments of theinvention are illustrated.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a longitudinal sectional view of an air discharge assemblyunit;

FIG. 2 is an exploded view of the air discharge assembly unit accordingto FIG. 1 with a first assembly unit part and with a second assemblyunit part;

FIG. 3 is an axial view of the air discharge assembly unit according toFIG. 1, partly cut away along a line III-III in FIG. 1; and

FIG. 4 is a schematic diagram of an air routing system with two airdischarge assembly units according to FIG. 1.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

Referring to the drawings in particular, an air discharge assembly unitis generally designated by 10 in FIG. 1. The air discharge assembly unitcomprises a first assembly unit part 12 as well as a second assemblyunit part 14 rotatable about a longitudinal axis K of the duct inrelation to the first assembly unit part 12.

The first assembly unit part 12 is provided with a, for example,essentially cylindrical outer wall 16. The outer wall 16 is inconnection with a duct wall 22 in an axial end area 20 providing aprimary air inlet area 18. The duct wall 22 is designed such that ittapers in the direction of the longitudinal axis K of the duct startingfrom the primary air inlet area 18, which leads to a reduction of theflow cross-sectional area of an air routing duct 28 defined by the ductwall 22. A duct area 30 with a minimal flow cross-sectional area isformed in the end area 24 of the duct wall 22.

The outer wall 16 is joined by a flange-like, essentially radiallyextending expansion area 32 approximately in the axial area of the endarea 24 of the duct wall 22. Starting from this expansion area 32, wallsections 34 providing essentially a ring-shaped wall configurationextend in the circumferential direction at circumferentially spacedlocations from one another starting from said expansion area 32.

The second assembly unit part 14 provides a closing wall 36 set in aconical or truncated conical pattern in the upstream direction. An airoutlet opening 38 is provided in the closing wall 36 in an area that isa central area or an area that is preferably coaxial or concentric tothe longitudinal axis K of the duct, and this air outlet area 38provides essentially an air outlet area 40 of the air discharge assemblyunit 10. The air routing duct 28 enclosed by the two assembly unit parts12, 14 ends at this air outlet area 40 or in the area of the air outletarea 38.

A secondary air inlet area 41 with a primary secondary air inlet opening42 is formed between the axial end area 24 of the duct wall and theclosing wall 36 of the second assembly unit part 14. This primarysecondary air inlet opening preferably extends without interruption in aring-shaped pattern around the longitudinal axis K of the duct andaround the air routing duct 28 and thus it directly adjoins axially theduct wall 22. As is indicated by broken lines in FIG. 1, this primarysecondary air inlet opening 42, extending in a ring-shaped patternaround the longitudinal axis K of the duct, has an essentially truncatedcone-shaped opening cross-sectional geometry. This causes the flow crosssection of the air routing duct 28 to have an increasing flowcross-sectional area starting from the duct area 30 with minimal flowcross-sectional area at the axial end area 24 of the duct wall 22corresponding to the geometry, indicated by broken lines, of the primarysecondary air inlet opening 42, towards the outlet opening 38. This alsoresults especially from the fact that the outlet opening 38 has a largerflow cross-sectional area than the duct area 30 with minimal flowcross-sectional area if, for example, the geometry of the cross sectionis the same as that of the flow duct 28 in the axial end area 24 of theduct wall 22.

A circumferential wall 44 is provided at the second assembly unit part14 such that the circumferential wall 44 radially adjoins the closingwall 36 of the second assembly unit part 14 on the outside. Thecircumferential wall 44 is advantageously essentially of a cylindricalshape and is dimensioned such that it extends radially around the wallsections 34 at the first assembly unit part 12 on the outside in theassembled state shown in FIG. 1. Together with the wall sections 34, thecircumferential wall 44 forms secondary secondary air inlet openings 46with variable flow cross-sectional area. Secondary air N can enter asecondary air flow space 48 surrounding the primary secondary air inletopening 42 in a ring-shaped pattern through the secondary air inletopenings 46. The secondary air N reaches the primary secondary air inletopening 42 through the secondary air flow space 48. The secondary airpassing through the primary secondary air inlet opening 42 enters theair routing duct 28 surrounded by the two assembly unit parts 12, 14 andthus is added to the primary air H being routed therein as arriving fromthe primary air inlet area 18. These two air streams of the primary airH and secondary air N mix with one another and are discharged as the airstream L from the air discharge assembly unit 10.

First secondary opening areas 50 that are open away from the flange-likeexpansion area 32 are formed in the direction of the longitudinal axis Kof the duct in the circumferential direction between the wall sections34 of the first assembly unit part. As this is illustrated in FIG. 3,the circumferential extension of these first secondary opening areas 50may correspond to the circumferential extension of the wall sections 34.For example, the angle of the circumferential extension may be 36°.

Corresponding to the first secondary opening areas 50, second secondaryopening areas 52 are provided in the circumferential wall 44 of thesecond assembly unit part 14. These may have the same circumferentialextension as the first secondary opening areas 50, and a wall section 54of the circumferential wall 44, which said wall section has acircumferential extension that may correspond to that of a respectivewall section 34 at the first assembly unit part 12, is located in thecircumferential direction between two secondary opening areas each.

The wall sections 34 and the circumferential wall 44 overlap each otherin the direction of the longitudinal axis K of the duct in the assembledstate shown in FIG. 1, so that the circumferential wall 44advantageously ends flush with the rear side 56 of the flange-likeexpansion area 32, which said rear side is oriented in the direction ofthe primary air inlet area 18. The two assembly unit parts 12, 14 arerotatable in relation to one another about the longitudinal axis K ofthe duct and may be arranged, for example, in the relative rotationalposition shown in FIG. 3. The wall sections 34 and 54 are positioned inrelation to one another in this relative rotational position such thatthey do not have essentially any circumferential overlap. This meansthat the first secondary opening areas 50 and the second secondaryopening areas 52 essentially also fail to overlap each other in thecircumferential direction and the flow path to the secondary air flowspace 48 is thus blocked. The secondary air inlet openings 46 are thusblocked or have a flow cross-sectional area in the range of zero.

If the two assembly unit parts 12, 14 are rotated in relation to oneanother starting from the relative rotational positioning shown in FIG.3, the first and second secondary opening areas 50, 52 will assume aposition in which they overlap each other in the circumferentialdirection, so that the flow cross-sectional area of the secondarysecondary air inlet openings 46 provided by a first secondary openingarea 50 and a second secondary opening area 52 will correspondinglyincrease as well. The maximal flow cross-sectional area of the secondarysecondary air inlet openings 46 is present if the first and secondsecondary opening areas 50, 52 and correspondingly the wall sections 34and 54 fully overlap in the circumferential direction.

The quantity of the secondary air N to be added to the stream of theprimary air H can thus be set by setting the relative positioningbetween the two assembly unit parts 12, 14 and correspondingly bysetting the flow cross-sectional area of the secondary secondary airinlet openings 46. Since the secondary air N mixes with the primary airH in front of and in the area of the air outlet opening 38 and since,especially if the primary air H is heated air, this air may have ahigher temperature than the secondary air N, a stream of air that willhave a mixed temperature in the range between the temperature of theprimary air and the temperature of the secondary air N will bedischarged in the air outlet area 40.

It should be noted in this connection that the cross-sectional geometryor the variation of the cross-sectional area of the secondary secondaryair inlet openings 46 can, of course, also be influenced by themagnitude of the circumferential extension of the first and secondsecondary opening areas 50, 52 and of the wall sections 34, 54.Embodiments that may deviate from the embodiment shown in FIG. 3 buthave equal circumferential extension are, of course, possible. Forexample, first or/and second secondary opening areas 50, 52 withdifferent circumferential extensions could be provided.

Furthermore, it should be noted that for a connection of the twoassembly unit parts 12, 14 with one another, which permits a relativerotary motion but is nevertheless fixed, for example, one of theassembly unit parts may have, on an outer circumferential side, a radialprojection, which can mesh with a corresponding depression on the innercircumference of the other component in a catch-like manner. The twoassembly unit parts 12, 14 may be advantageously provided as plasticparts, in which case they may be designed with the structural aspectsrecognizable in the figures, i.e., with the different walls or wallsections, as integral components each.

FIG. 4 shows an air routing system 60, in which two air dischargeassembly units 10 having the design explained above may be provided. Forexample, a fuel-operated vehicle heater 62, to which combustion air isfed through a combustion air feed arrangement and fuel through a fuelfeed arrangement, is associated with the air routing system 60. The heatgenerated during the combustion operation can be transmitted to theprimary air H, which is drawn in, for example, from the surroundingarea. The primary air H heated in the heater 62 leaves said heater via aflow duct 64, which is open in a first branching area 66 towards theupstream air discharge assembly unit 10, and leads to the downstream airdischarge assembly unit 10 in a second branching area or end area 68.Both air discharge assembly units 10 are positioned and oriented suchthat the respective air stream L leaving these flows into the interiorspace 70 of a vehicle. Further, both air discharge assembly units 10 arearranged such that the sides 56 of the flange-like expansion areas 32are in contact with a wall 72 surrounding the interior space 70. Fixedmounting can be achieved, for example, by a fastening member surroundingthe outer wall 16 on the rear side of said wall 72.

The secondary secondary air inlet openings 46 of the two air dischargeassembly units 10 are open towards the interior space 70 of the vehiclein the arrangement shown in FIG. 4, so that the secondary air N to bemixed with the primary air H is drawn off from the interior space 70 ofthe vehicle. The amount of the secondary air N to be mixed with theprimary air H can be set individually in each of the air dischargeassembly units 10 by rotating the respective second assembly unit part14 in the above-described manner. It thus becomes possible to set thetemperature of the air L being routed into the interior space 70 of thevehicle by varying the percentage of the secondary air N to be added tothe primary air H, without the need to change the heat output of theheater 62.

Since, furthermore, the air discharge assembly units 10 operateaccording to the principle of a Venturi nozzle and when the primary airis flowing, the secondary air is drawn in by the static vacuum presentin the tapering air routing duct, no further feed means are necessary toachieve the addition of the secondary air. It should be noted out herethat this effect can be achieved especially efficiently when the primarysecondary air inlet opening is positioned as close as possible to thesite where the air routing duct has its minimal flow cross-sectionalarea and the primary air flowing therein correspondingly has the highestflow velocity. However, the positioning of a secondary air inlet area inthe area of the duct area with minimal flow cross-sectional area alsocomprises, in the sense of the present invention, deviations from thisrequirement, which deviations also guarantee that the secondary air canenter the air routing duct where a static vacuum is generated in theprimary air stream based on an increased velocity of flow due to areduced flow cross-sectional area.

To make it possible to influence the direction of discharge of the air Lin the air outlet area 40, a routing surface arrangement provided withfins or the like may be arranged, for example, at the second assemblyunit part 14, and a change in the direction of discharge can beachieved, for example, by pivoting fins providing such routing surfaces.This means that the outlet opening can be divided into a plurality ofopening areas, either by pivotable fins or the like, or by a stationarygrid arrangement or fin arrangement, optionally to influence thedirection of discharge. It is advantageous in this case as well if theoverall flow cross-sectional area of the opening sections of the airoutlet opening 38, which opening sections are generated by such adivision, is larger than the flow cross-sectional area in the duct area30 with minimal flow cross-sectional area.

As is shown in FIGS. 1 and 2, the air routing duct may extend in thedirection of a longitudinal axis K of the duct, which axis extends in astraight line, and may be provided with a flow cross-sectional areadecreasing in this direction. The air routing duct 28 could, inprinciple, also have a curved design, in which case the longitudinalaxis of the duct is curved correspondingly. References to a radialpositioning in relation to the longitudinal axis of the duct shouldalways be understood to mean such that the relative positioning is to beconsidered in the axial area of the air routing duct or of thelongitudinal axis of the duct in which a formation having a certainpositioning relative to the longitudinal axis of the duct is present.

While specific embodiments of the invention have been shown anddescribed in detail to illustrate the application of the principles ofthe invention, it will be understood that the invention may be embodiedotherwise without departing from such principles.

What is claimed is:
 1. An air discharge assembly unit for routing airinto an interior space of a vehicle, the air discharge assembly unitcomprising: an air routing duct for routing primary air from a primaryair inlet area to an air outlet area, wherein the air routing duct has aflow cross-sectional area that decreases, at least in some sections, inthe direction of the air outlet area, away from the primary air inletarea, to a duct area with a minimal flow cross-sectional area; and asecondary air inlet area for the inlet of secondary air into the airrouting duct, in an area of the duct area with the minimal flowcross-sectional area.
 2. An air discharge assembly unit in accordancewith claim 1, wherein the secondary air inlet area comprises at leastone primary secondary air inlet opening, wherein the secondary air isadded to the primary air through the at least one primary secondary airinlet opening.
 3. An air discharge assembly unit in accordance withclaim 2, wherein the primary secondary air inlet opening surrounds alongitudinal axis of the air routing duct in a ring-shaped pattern. 4.An air discharge assembly unit in accordance with claim 3, wherein theprimary secondary air inlet opening has a truncated cone-shaped openingcross-sectional geometry.
 5. An air discharge assembly unit inaccordance claim 2, wherein the secondary air inlet area furthercomprises at least one secondary secondary air inlet opening, whereinthe at least one secondary secondary air inlet opening is open towards asecondary air flow space leading to the at least one primary secondaryair inlet opening.
 6. An air discharge assembly unit in accordance withclaim 5, wherein the at least one secondary secondary air inlet openingis arranged radially outside the at least one primary secondary airinlet opening relative to a longitudinal axis of the air routing duct.7. An air discharge assembly unit in accordance with claim 6, whereinthe secondary air flow space surrounds the longitudinal axis of the ductin an essentially ring-shaped pattern.
 8. An air discharge assembly unitin accordance with claim 5, wherein a flow cross-sectional area of theat least one secondary secondary air inlet opening is variable.
 9. Anair discharge assembly unit in accordance with claim 1, wherein the airrouting duct has a first duct wall of a first assembly unit part,wherein the duct wall tapers, at least in some areas, away from theprimary air inlet area.
 10. An air discharge assembly unit in accordancewith claim 9, wherein the duct wall provides the duct area with minimalflow cross-sectional area, in an end area of said duct wall, located ata distance from the primary air inlet area.
 11. An air dischargeassembly unit in accordance with claim 9, wherein a second assembly unitpart has an air outlet opening for the primary air being routed throughthe air routing duct and the at least one primary secondary air inletopening for the secondary air added to the primary air, wherein the airoutlet opening essentially defines the air outlet area.
 12. An airdischarge assembly unit in accordance with claim 1, wherein the airoutlet opening has a larger flow cross-sectional area than the duct areawith the minimal flow cross-sectional area.
 13. An air dischargeassembly unit in accordance with claim 2, wherein: the air routing ducthas a first duct wall of a first assembly unit part; a second assemblyunit part has an air outlet opening for the primary air being routedthrough the air routing duct and the at least one primary secondary airinlet opening for the secondary air added to the primary air; and the atleast one primary secondary air inlet opening is defined in an areaproviding the air outlet opening between the duct wall of the firstassembly unit part and the second assembly unit part.
 14. An airdischarge assembly unit in accordance with claim 8, wherein: the airrouting duct has a first duct wall of a first assembly unit part; asecond assembly unit part has an air outlet opening for the primary airbeing routed through the air routing duct and the at least one primarysecondary air inlet opening for the secondary air added to the primaryair; and the first assembly unit part has at least one first secondaryopening area, the second assembly unit part has at least one secondsecondary opening area, and the at least one first secondary openingarea and the at least one second secondary opening area are movable inrelation to one another by rotating the second assembly unit part inrelation to the first assembly unit part for providing the at least onesecondary secondary air inlet opening with variable flow cross-sectionalarea.
 15. An air routing system for routing air in an interior spacearea of a vehicle, the air routing system comprising: at least one airdischarge assembly unit comprising: an air routing duct for routingprimary air from a primary air inlet area to an air outlet area, whereinthe air routing duct has a flow cross-sectional area that decreases, atleast in some sections, in the direction of the air outlet area, awayfrom the primary air inlet area, to a duct area with a minimal flowcross-sectional area; and a secondary air inlet area for the inlet ofsecondary air into the air routing duct, in an area of the duct areawith the minimal flow cross-sectional area.
 16. An air routing system inaccordance with claim 15, wherein the secondary air inlet area comprisesat least one primary secondary air inlet opening, wherein the secondaryair is added to the primary air through the at least one primarysecondary air inlet opening.
 17. An air routing system in accordanceclaim 16, wherein the secondary air inlet area further comprises atleast one secondary secondary air inlet opening, wherein the at leastone secondary secondary air inlet opening is open towards a secondaryair flow space leading to the at least one primary secondary air inletopening.
 18. An air routing system in accordance with claim 17, whereinthe air outlet area as well as at least one secondary secondary airinlet area open towards the space area.
 19. An air routing system inaccordance with claim 16, wherein: the air routing duct has a first ductwall of a first assembly unit part; a second assembly unit part has anair outlet opening for the primary air being routed through the airrouting duct and the at least one primary secondary air inlet openingfor the secondary air added to the primary air; and the at least oneprimary secondary air inlet opening is defined in an area providing theair outlet opening between the duct wall of the first assembly unit partand the second assembly unit part.
 20. An air routing system inaccordance with claim 17, wherein: the air routing duct has a first ductwall of a first assembly unit part; a second assembly unit part has anair outlet opening for the primary air being routed through the airrouting duct and the at least one primary secondary air inlet openingfor the secondary air added to the primary air; the at least onesecondary secondary air inlet opening is arranged radially outside theat least one primary secondary air inlet opening relative to alongitudinal axis of the air routing duct and the first assembly unitpart has at least one first secondary opening area, the second assemblyunit part has at least one second secondary opening area, and the atleast one first secondary opening area and the at least one secondsecondary opening area are movable in relation to one another byrotating the second assembly unit part in relation to the first assemblyunit part for providing the at least one secondary secondary air inletopening with variable flow cross-sectional area.